Block & tackle/pulley for lifting bulk bag of logs

[charlieb]

I'm looking for something to sling over a beam in the drying shed so that I can lift a bulk bag of logs up 2m and reverse the landy underneath it.  A small step towards reducing the amount of handling we do for a single load of seasoned logs.

Any pointers on what sort of tackle system I'd need, where I can get hold of one, what rope is best to go with it and how much I'd need, and anything to watch out for?  

Here's my guestimate so far:

Bag weighs roughly 250kg (http://arbtalk.co.uk/forum/firewood-forum/14690-bulk-bag-weight.html). Which = 3x me so I'd need at least a 4x gearing ( 'mechanical advantage seems to be the term').

Wikipedia has the following helpful table (http://en.wikipedia.org/wiki/Block_and_tackle):
Gun Tackle: 2
Luff Tackle: 3
Double Tackle: 4
Gyn Tackle: 5
Threefold purchase: 6

So I'm looking at a double tackle set-up, with at least 14m of rope (2m lift x4, plus whatever the tackle needs). There's not much point in getting something with more capacity, as the beam is likely to go before the tackle does.   Where to start?

Thanks for any suggestions.  Incidentally, in due course i'll be building a decent sized dutch barn to add to the current shed. It'd have reinforced beams to do this more effectively, and, probably, runners for a proper lifting point. For now I'll just jump up a ladder to sling the top hook over a beam. This is more about experimenting with bulk bags than it is about efficient lifting.   

PS needless to say, I don't have access to a forklift, and the tractor can't get into the shed.

 

[johnrae]

I take it an electric hoist is out of the question.  The likes of Aldi do them quite cheap on occasion and are well within your load range.   They have the advantage of having a brake which means you can lift then move the landy under the load.  Alternatively Machinemart do a manual winch which will easily lift your load

[charlieb]

Yes, electric out of the question.  And to be honest I like the idea of a block and tackle.  I think a winch would be harder to mvoe about - they're usually designed for a fixed position.     When I build the dutch barn then I'd get a winch, probably, but for now I want to get hold of a simple block. Hopefully cheap as chips.

Something like this I guess: http://www.ebay.co.uk/itm/Light-wieght-block-and-tackle-/200673670113?pt=UK_Lifting_Moving_Equipment&hash=item2eb91533e1

[AlanM]

what you need is a chain hoist, I use one for lifting logs, ie, whole trees, for building. You can egt them in various lift heights, and a range of weight capacities. For example mine is a 6m lift of 1 tonne. It uses an endless chain, and the load is braked until you move it up or down. bought my one off ebay for around £40-£50  i think, but you should find them in Tool station, screwfix maybe, machine mart.

Alan

[djh]

Don't forget to figure out how you're going to make fast when you've hauled the bag up. You'll need to transfer the rope under load onto a cleat or post or something. [edit] You might need more 'mechanical advantage' to be able to do that, depending on the exact arrangement.

The rope needs to be strong enough, and also comfortable to pull (large enough diameter and moderately rough surface). Also needs to roughly match the pulleys. Other than that, any sort of rope should do.

A chain hoist would be an alternative.[as posted by Alan]

[Baz]

Most self contained hoists like a chain hoist really need you to be quite close to them and able to pull down vertically on the rope/chain. You will find it rather irritating to be pulling the rusty chain over the edge of the big sack when it is near the top.
I think you just need a manual ratchet winch of the sort used to pull small boats up onto a trailer http://www.morriscranes.co.uk/hoists/hoistsAndWinches/manualWinches/index.htm with a couple of pulley blocks to improve the ratio if the handle isn't long enough.
Sounds like you are trying to lower it in through the roof if you are pulling up to 2m, the back of a Landy is only 2'6" unless you have silly tyres.

Bonus points for being eco and not getting an electric one though.

By the way in case you don't know the cheap lever wire rope winches http://www.toolstation.com/shop/Automotive/Jacks+Stands+Winches/Pull+Winch+4000kg/d60/sd3228/p98107
often called a 'come along' in the 'states are not safe for hoisting, only horizontal pulling, as their let down mechanisn is a bit dodgey - like a ratchet strap system.

[charlieb]

Bonus points for being eco and not getting an electric one though.

Nice to get the bonus points Baz, but there's no electric within half a mile of the shed so they're not really deserved!

Thanks for pickup landy measurements - I'm going on guesswork as am at work in London, 500 miles away from the shed and landy - but I would have to lift the bags up over the edge of the pick-up, as I don't think the tailgate gap is as wide as the bulk bag. Also  I'd like scope for lifting other things right up to the rafters, though, so I thought I'd just go with 2m.   But if I'm only lifting bags a m or so the chain-over-bag irritation may be less I suppose. 

[johnrae]

And one more obvious question  -  will your barn joist take a 250kg point load.  As a minimum it should be "tested" to 500kg to give you confidence

[acresswell]

Don't forget that if you've got a landy then you do have the option of electric - using 12V, for example:
http://www.machinemart.co.uk/shop/product/details/t2000-12v-dc-winch-907kg-pull?da=1&TC=SRC-12v winch (£96 inc vat)

or the very simple hand winch referred to by johnrae (£25-30)
http://www.machinemart.co.uk/shop/range/guid/F201DD23-EFF4-4350-A209-03F6427F58A7

or a tirfor-type winch?  Always useful for other jobs... they are often perceived as slow, but over a 2metre lift, it'd only be about 33 strokes. I bought mine from here:
http://www.liftingequipmentdirectuk.co.uk/wire_rope_winch.html
Not genuine tirfor but I didn't have to sell a kidney either... (about £200)

or I can attest to the simplicity of chain hoists, but also their capacity for jamming when pulled at an angle

[acresswell]

Just a thought... if you do decide to stick with pulling a rope, then it'd be worth seeing if you can manage to tie on a carabiner (or similar) at the appropriate point so that all you have to do is slip it over a hook. Don't underestimate how hard it is to tie a rope off when it's got a large load on it... especially if it's close to your body weight and you're not pulling straight down (it'll tend to pull you over). Of course the law of S.O.D is that the carabiner would need to go through your pulley system. 

I used to work in a theatre flying backcloths etc... there were two flying systems, one using counterweights and the other using traditional hemp lines. Nobody ever used the hemp lines if they could avoid it. Even a small counterweight (25kg) could make a sizeable difference to the force you have to exert personally. Ships chandlers may be a useful source of bits, but do try playing tug-of war with a bit of rope before buying it if possible...  there's a big difference between their effect on your hands. Natural fibres tend to be the softest on your hands, but will also rot in time.

Why not use the landrover itself to do the pulling then tie the rope off and only lower it manually?

[qeipl]

I use tackles a lot for lifting and pulling. Sailing gear is ideal.
Barton plain bearing yacht blocks are good quality and value - http://marinestore.co.uk/barton-blocks-size-4.html
Size 4 takes a 12mm rope, which is the minimum for getting a good grip.

Upper block - fiddle, swivel & becket.
Lower block - fiddle, swivel only.
That'll give you a 4:1 advantage.

If you've got limited headroom then double blocks (instead of fiddles) will give you and extra few inches of lift (but fiddles will run better when you're moving around while pulling the fall of the tackle).

A belaying pin (e.g. a steel rod protruding from either side of a structural member of the shed) is easiest for controlling and securing the fall when under load.
If the load is a bit too heavy for you to haul up easily you can take half a turn around the belaying pin and 'sweat' the fall - throwing your weight at right angles onto the fall and then pulling down towards the pin while you take up the slack around the pin.

[charlieb]

Many thanks to all. (I knew this one would be a good question for Navitron Forum).

I'm pretty sure a chain hoist is what I'm after - I need to be able to move it from place to place (having positioned bags uneder the beams).   There seem to be lots available for #30-40.   Am I right in thinking that they're designed with gearing so that one normal-strength man can lift whatever the rated capacity is? - none of the ones on ebay seem to mention a gearing, so that's all I can think of as an explanation.     

If that doesn't work I'll have a think about that sailing gear.  It looks like satisfying stuff.

John. That remains to be seen to be honest. I'll do some playing around on it before I splash out on anything, although I'm pretty sure a chain hoist will come in useful lots in the future.  On that note, can anyone tell me what the good quality brands are?  Thanks again.
C

[AlanM]

Hi Charlie,
yes, they are geared so you can lift/pull with normal strength. The other advantage is you can raise, walk off, reverse landy, then lower without having to faff about tying things off.
Or, and this just ocurred to me, you could mount the chain hoist on a pulley, which can run on a rail, perhaps a section of I-beam, which could spread the load over many joists, or allow access to the whole length of the building.
 I have used chain hoists off -vertical and have had no problems with loads snagging, keep the chains clean and lightly oiled to keep rust at bay and you'll be fine.
Alan

[charlieb]

Yep, that I-beam idea had occured to me too Alan. If beams look dodgy I'll bodge do something like that.  The next bodge would be some sort of A-frame that can be put in the landy so I can then lift the bag out of the landy at customer's house... though might be cheaper/easier just to buy a flatbed with crane! 

[guydewdney]

engine hoist? as in self supporting crane type

http://www.machinemart.co.uk/shop/product/details/cfc1000lr-1t-long-reach-workshop-crane